There are a variety of products which include or are associated with a modem connected to the telephone system for automatically communicating data, such as billing information, back to a control station. For example users of television receivers capable of receiving and processing television signals provided via a cable distribution network or a satellite in earth orbit are often required to pay fees. There is a basic connection fee for access to the service and a certain group of channels and a so called "pay for view" fee for access to special event programs, such as movies and sporting events. "Pay for view" fee billing information is accumulated and stored in the television receiver on a per use basis and is automatically transmitted ("downloaded") to a billing center via a modem. To this end, the modem initiates a "callback" to the billing center at regular, for example, monthly intervals. Usually the callbacks are paid for by the television signal provider.
A successful callback involves the initiation of a telephone call from the modem of the television receiver to a modem at the billing center, acknowledgment by the modem at the billing center (answering the telephone call and establishing a proper "handshaking" protocol) and a successful transfer of the billing information. Unfortunately, a callback may be unsuccessful for a variety of reasons. As a result, the television signal provider will not have an accurate basis for calculating the fee owed by the user. In addition, since old billing information for previously viewed programs will not have been transferred to the billing center from the television receiver, it will not be "cleared". Therefor, at some point, the user will be unable to select new programs for viewing. Accordingly, it is desirable to minimize billing problems due to unsuccessful modem callbacks.
One technique for avoiding billing problems due to unsuccessful callbacks is to cause the modem, after an unsuccessful callback, to initiate callbacks at relatively frequent intervals compared to the normal intervals until there is a successful callback. For example, the modem may be caused, after an unsuccessful callback, to callback at intervals between ten minutes and two hours until there is a successful callback. As a modification of this technique, the modem may be caused to callback at intervals which alternate between a very short interval, such as ten minutes, and a somewhat longer interval, such as an hour. However, the technique of utilizing more frequent callbacks may not result in a successful callback, and under some circumstances may cause the television signal provider (who is paying for the call backs) to incur unnecessary and unreasonably high expenses due to the numerous frequent callback attempts.